Hearing aid



FIG. 1 is a first perspective view of a hearing aid showing our design;

FIG. 2 is a second perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a top side view thereof; and,

FIG. 8 is a bottom view thereof.

The broken lines in the drawings depict portions of the hearing aid thatform no part of the claimed design.

CLAIM The ornamental design for a hearing aid, as shown and described.